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Bromfield ESP, Cloutier S. Bradyrhizobium ontarionense sp. nov., a novel bacterial symbiont isolated from Aeschynomene indica (Indian jointvetch), harbours photosynthesis, nitrogen fixation and nitrous oxide (N 2O) reductase genes. Antonie Van Leeuwenhoek 2024; 117:69. [PMID: 38647727 PMCID: PMC11035471 DOI: 10.1007/s10482-024-01940-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/02/2024] [Indexed: 04/25/2024]
Abstract
A novel bacterial symbiont, strain A19T, was previously isolated from a root-nodule of Aeschynomene indica and assigned to a new lineage in the photosynthetic clade of the genus Bradyrhizobium. Here data are presented for the detailed genomic and taxonomic analyses of novel strain A19T. Emphasis is placed on the analysis of genes of practical or ecological significance (photosynthesis, nitrous oxide reductase and nitrogen fixation genes). Phylogenomic analysis of whole genome sequences as well as 50 single-copy core gene sequences placed A19T in a highly supported lineage distinct from described Bradyrhizobium species with B. oligotrophicum as the closest relative. The digital DNA-DNA hybridization and average nucleotide identity values for A19T in pair-wise comparisons with close relatives were far lower than the respective threshold values of 70% and ~ 96% for definition of species boundaries. The complete genome of A19T consists of a single 8.44 Mbp chromosome and contains a photosynthesis gene cluster, nitrogen-fixation genes and genes encoding a complete denitrifying enzyme system including nitrous oxide reductase implicated in the reduction of N2O, a potent greenhouse gas, to inert dinitrogen. Nodulation and type III secretion system genes, needed for nodulation by most rhizobia, were not detected. Data for multiple phenotypic tests complemented the sequence-based analyses. Strain A19T elicits nitrogen-fixing nodules on stems and roots of A. indica plants but not on soybeans or Macroptilium atropurpureum. Based on the data presented, a new species named Bradyrhizobium ontarionense sp. nov. is proposed with strain A19T (= LMG 32638T = HAMBI 3761T) as the type strain.
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Affiliation(s)
- Eden S P Bromfield
- Agriculture and Agri-Food Canada, 960 Carling Ave., Ottawa, K1A 0C6, Canada.
| | - Sylvie Cloutier
- Agriculture and Agri-Food Canada, 960 Carling Ave., Ottawa, K1A 0C6, Canada
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2
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Tisseyre P, Cartieaux F, Chabrillange N, Gully D, Hocher V, Svistoonoff S, Gherbi H. Setting up Agrobacterium tumefaciens-mediated transformation of the tropical legume Aeschynomene evenia, a powerful tool for studying gene function in Nod Factor-independent symbiosis. PLoS One 2024; 19:e0297547. [PMID: 38625963 PMCID: PMC11020691 DOI: 10.1371/journal.pone.0297547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 01/09/2024] [Indexed: 04/18/2024] Open
Abstract
Most legumes are able to develop a root nodule symbiosis in association with proteobacteria collectively called rhizobia. Among them, the tropical species Aeschynomene evenia has the remarkable property of being nodulated by photosynthetic Rhizobia without the intervention of Nod Factors (NodF). Thereby, A. evenia has emerged as a working model for investigating the NodF-independent symbiosis. Despite the availability of numerous resources and tools to study the molecular basis of this atypical symbiosis, the lack of a transformation system based on Agrobacterium tumefaciens significantly limits the range of functional approaches. In this report, we present the development of a stable genetic transformation procedure for A. evenia. We first assessed its regeneration capability and found that a combination of two growth regulators, NAA (= Naphthalene Acetic Acid) and BAP (= 6-BenzylAminoPurine) allows the induction of budding calli from epicotyls, hypocotyls and cotyledons with a high efficiency in media containing 0,5 μM NAA (up to 100% of calli with continuous stem proliferation). To optimize the generation of transgenic lines, we employed A. tumefaciens strain EHA105 harboring a binary vector carrying the hygromycin resistance gene and the mCherry fluorescent marker. Epicotyls and hypocotyls were used as the starting material for this process. We have found that one growth medium containing a combination of NAA (0,5 μM) and BAP (2,2 μM) was sufficient to induce callogenesis and A. tumefaciens strain EHA105 was sufficiently virulent to yield a high number of transformed calli. This simple and efficient method constitutes a valuable tool that will greatly facilitate the functional studies in NodF-independent symbiosis.
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Affiliation(s)
- Pierre Tisseyre
- IRD (French National Research Institute for Sustainable Development), UMR QualiSud, IRD-MONTPELLIER, Montpellier, France
| | - Fabienne Cartieaux
- IRD (French National Research Institute for Sustainable Development), UMR PHIM (Plant Health Institute of Montpellier), Montpellier, France
| | - Nathalie Chabrillange
- IRD (French National Research Institute for Sustainable Development), UMR PHIM (Plant Health Institute of Montpellier), Montpellier, France
| | - Djamel Gully
- IRD (French National Research Institute for Sustainable Development), UMR PHIM (Plant Health Institute of Montpellier), Montpellier, France
| | - Valérie Hocher
- IRD (French National Research Institute for Sustainable Development), UMR PHIM (Plant Health Institute of Montpellier), Montpellier, France
- Laboratoire commun de Microbiologie IRD/ISRA/UCAD, Centre de recherche de Bel Air, Dakar, Sénégal
| | - Sergio Svistoonoff
- IRD (French National Research Institute for Sustainable Development), UMR PHIM (Plant Health Institute of Montpellier), Montpellier, France
| | - Hassen Gherbi
- IRD (French National Research Institute for Sustainable Development), UMR PHIM (Plant Health Institute of Montpellier), Montpellier, France
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Manantsoa FF, Rakotoarisoa MF, Chaintreuil C, Razakatiana ATE, Gressent F, Pervent M, Bourge M, Andrianandrasana MD, Nouwen N, Randriambanona H, Ramanankierana H, Arrighi JF. Occurrence and diversity of stem nodulation in Aeschynomene and Sesbania legumes from wetlands of Madagascar. Sci Rep 2024; 14:5024. [PMID: 38424094 PMCID: PMC10904833 DOI: 10.1038/s41598-024-55247-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 02/21/2024] [Indexed: 03/02/2024] Open
Abstract
Legumes have the ability to establish a nitrogen-fixing symbiosis with soil rhizobia that they house in specific organs, the nodules. In most rhizobium-legume interactions, nodulation occurs on the root. However, certain tropical legumes growing in wetlands possess a unique trait: the capacity to form rhizobia-harbouring nodules on the stem. Despite the originality of the stem nodulation process, its occurrence and diversity in waterlogging-tolerant legumes remains underexplored, impeding a comprehensive analysis of its genetics and biology. Here, we aimed at filling this gap by surveying stem nodulation in legume species-rich wetlands of Madagascar. Stem nodulation was readily observed in eight hydrophytic species of the legume genera, Aeschynomene and Sesbania, for which significant variations in stem nodule density and morphology was documented. Among these species, A. evenia, which is used as genetic model to study the rhizobial symbiosis, was found to be frequently stem-nodulated. Two other Aeschynomene species, A. cristata and A. uniflora, were evidenced to display a profuse stem-nodulation as occurs in S. rostrata. These findings extend our knowledge on legumes species that are endowed with stem nodulation and further indicate that A. evenia, A. cristata, A. uniflora and S. rostrata are of special interest for the study of stem nodulation. As such, these legume species represent opportunities to investigate different modalities of the nitrogen-fixing symbiosis and this knowledge could provide cues for the engineering of nitrogen-fixation in non-legume crops.
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Affiliation(s)
- Faustin F Manantsoa
- Laboratoire de Microbiologie de l'Environnement-Centre National de Recherches sur l'Environnement, BP 1739, Fiadanana, Antananarivo, Madagascar
| | - Marrino F Rakotoarisoa
- Department of Ethnobotany and Botany, National Center for Applied Pharmaceutical Research, Antananarivo 101, Madagascar
| | - Clémence Chaintreuil
- Plant Health Institute of Montpellier (PHIM), University Montpellier/IRD/INRAE/CIRAD/SupAgro, Campus de Baillarguet, 34398, Montpellier, France
| | - Adamson T E Razakatiana
- Laboratoire de Microbiologie de l'Environnement-Centre National de Recherches sur l'Environnement, BP 1739, Fiadanana, Antananarivo, Madagascar
| | - Frédéric Gressent
- Plant Health Institute of Montpellier (PHIM), University Montpellier/IRD/INRAE/CIRAD/SupAgro, Campus de Baillarguet, 34398, Montpellier, France
| | - Marjorie Pervent
- Plant Health Institute of Montpellier (PHIM), University Montpellier/IRD/INRAE/CIRAD/SupAgro, Campus de Baillarguet, 34398, Montpellier, France
| | - Mickaël Bourge
- Cytometry Facility, Institute for Integrative Biology of the Cell (I2BC), Imagerie-Gif, Université Paris-Saclay, CEA, CNRS, 91198, Gif-Sur-Yvette, France
| | - Martial D Andrianandrasana
- Laboratoire de Microbiologie de l'Environnement-Centre National de Recherches sur l'Environnement, BP 1739, Fiadanana, Antananarivo, Madagascar
| | - Nico Nouwen
- Plant Health Institute of Montpellier (PHIM), University Montpellier/IRD/INRAE/CIRAD/SupAgro, Campus de Baillarguet, 34398, Montpellier, France
| | - Herizo Randriambanona
- Laboratoire de Microbiologie de l'Environnement-Centre National de Recherches sur l'Environnement, BP 1739, Fiadanana, Antananarivo, Madagascar
| | - Heriniaina Ramanankierana
- Laboratoire de Microbiologie de l'Environnement-Centre National de Recherches sur l'Environnement, BP 1739, Fiadanana, Antananarivo, Madagascar
| | - Jean-François Arrighi
- Plant Health Institute of Montpellier (PHIM), University Montpellier/IRD/INRAE/CIRAD/SupAgro, Campus de Baillarguet, 34398, Montpellier, France.
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Nouwen N, Pervent M, El M’Chirgui F, Tellier F, Rios M, Horta Araújo N, Klopp C, Gressent F, Arrighi JF. OROSOMUCOID PROTEIN 1 regulation of sphingolipid synthesis is required for nodulation in Aeschynomene evenia. PLANT PHYSIOLOGY 2024; 194:1611-1630. [PMID: 38039119 PMCID: PMC10904325 DOI: 10.1093/plphys/kiad642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 12/03/2023]
Abstract
Legumes establish symbiotic interactions with nitrogen-fixing rhizobia that are accommodated in root-derived organs known as nodules. Rhizobial recognition triggers a plant symbiotic signaling pathway that activates 2 coordinated processes: infection and nodule organogenesis. How these processes are orchestrated in legume species utilizing intercellular infection and lateral root base nodulation remains elusive. Here, we show that Aeschynomene evenia OROSOMUCOID PROTEIN 1 (AeORM1), a key regulator of sphingolipid biosynthesis, is required for nodule formation. Using A. evenia orm1 mutants, we demonstrate that alterations in AeORM1 function trigger numerous early aborted nodules, defense-like reactions, and shorter lateral roots. Accordingly, AeORM1 is expressed during lateral root initiation and elongation, including at lateral root bases where nodule primordium form in the presence of symbiotic bradyrhizobia. Sphingolipidomics revealed that mutations in AeORM1 lead to sphingolipid overaccumulation in roots relative to the wild type, particularly for very long-chain fatty acid-containing ceramides. Taken together, our findings reveal that AeORM1-regulated sphingolipid homeostasis is essential for rhizobial infection and nodule organogenesis, as well as for lateral root development in A. evenia.
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Affiliation(s)
- Nico Nouwen
- Plant Health Institute of Montpellier (PHIM), IRD, UMR Univ Montpellier/IRD/SupAgro/INRAE/CIRAD, TA-A82/J Campus de Baillarguet, 34398 Montpellier, France
| | - Marjorie Pervent
- Plant Health Institute of Montpellier (PHIM), INRAE, UMR Univ Montpellier/IRD/SupAgro/INRAE/CIRAD, TA-A82/J Campus de Baillarguet, 34398 Montpellier, France
| | - Franck El M’Chirgui
- Plant Health Institute of Montpellier (PHIM), IRD, UMR Univ Montpellier/IRD/SupAgro/INRAE/CIRAD, TA-A82/J Campus de Baillarguet, 34398 Montpellier, France
| | - Frédérique Tellier
- Institut Jean-Pierre Bourgin (IJPB), INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Maëlle Rios
- Plant Health Institute of Montpellier (PHIM), IRD, UMR Univ Montpellier/IRD/SupAgro/INRAE/CIRAD, TA-A82/J Campus de Baillarguet, 34398 Montpellier, France
| | - Natasha Horta Araújo
- Plant Health Institute of Montpellier (PHIM), IRD, UMR Univ Montpellier/IRD/SupAgro/INRAE/CIRAD, TA-A82/J Campus de Baillarguet, 34398 Montpellier, France
| | - Christophe Klopp
- Plateforme Bioinformatique Genotoul, BioinfoMics, UR875 Biométrie et Intelligence Artificielle, INRAE, 31326 Castanet-Tolosan, France
| | - Frédéric Gressent
- Plant Health Institute of Montpellier (PHIM), INRAE, UMR Univ Montpellier/IRD/SupAgro/INRAE/CIRAD, TA-A82/J Campus de Baillarguet, 34398 Montpellier, France
| | - Jean-François Arrighi
- Plant Health Institute of Montpellier (PHIM), IRD, UMR Univ Montpellier/IRD/SupAgro/INRAE/CIRAD, TA-A82/J Campus de Baillarguet, 34398 Montpellier, France
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5
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Zhong C, Hu G, Hu C, Xu C, Zhang Z, Ning K. Comparative genomics analysis reveals genetic characteristics and nitrogen fixation profile of Bradyrhizobium. iScience 2024; 27:108948. [PMID: 38322985 PMCID: PMC10845061 DOI: 10.1016/j.isci.2024.108948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/12/2023] [Accepted: 01/15/2024] [Indexed: 02/08/2024] Open
Abstract
Bradyrhizobium is a genus of nitrogen-fixing bacteria, with some species producing nodules in leguminous plants. Investigations into Bradyrhizobium have recently revealed its substantial genetic resources and agricultural benefits, but a comprehensive survey of its genetic diversity and functional properties is lacking. Using a panel of various strains (N = 278), this study performed a comparative genomics analysis to anticipate genes linked with symbiotic nitrogen fixation. Bradyrhizobium's pan-genome consisted of 84,078 gene families, containing 824 core genes and 42,409 accessory genes. Core genes were mainly involved in crucial cell processes, while accessory genes served diverse functions, including nitrogen fixation and nodulation. Three distinct genetic profiles were identified based on the presence/absence of gene clusters related to nodulation, nitrogen fixation, and secretion systems. Most Bradyrhizobium strains from soil and non-leguminous plants lacked major nif/nod genes and were evolutionarily more closely related. These findings shed light on Bradyrhizobium's genetic features for symbiotic nitrogen fixation.
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Affiliation(s)
- Chaofang Zhong
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, College of Environmental and Life Sciences, Nanning Normal University, Nanning 530001, China
| | - Gang Hu
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, College of Environmental and Life Sciences, Nanning Normal University, Nanning 530001, China
| | - Cong Hu
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, College of Environmental and Life Sciences, Nanning Normal University, Nanning 530001, China
| | - Chaohao Xu
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, College of Environmental and Life Sciences, Nanning Normal University, Nanning 530001, China
| | - Zhonghua Zhang
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, College of Environmental and Life Sciences, Nanning Normal University, Nanning 530001, China
| | - Kang Ning
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Hubei Key Laboratory of Bioinformatics and Molecular-imaging, Department of Bioinformatics and Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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6
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Hata S, Tsuda R, Kojima S, Tanaka A, Kouchi H. Both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodules. PLANT SIGNALING & BEHAVIOR 2023; 18:2245995. [PMID: 37573516 PMCID: PMC10424618 DOI: 10.1080/15592324.2023.2245995] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/15/2023]
Abstract
In addition to rhizobia, many types of co-existent bacteria are found in leguminous root nodules, but their habitats are unclear. To investigate this phenomenon, we labeled Bradyrhizobium diazoefficiens USDA122 and Bradyrhizobium sp. SSBR45 with Discosoma sp. red fluorescent protein (DsRed) or enhanced green fluorescent protein (eGFP). USDA122 enhances soybean growth by forming effective root nodules, but SSBR45 does not form any nodules. Using low-magnification laser scanning confocal microscopy, we found that infected cells in the central zone of soybean nodules appeared to be occupied by USDA122. Notably, high-magnification microscopy after co-inoculation of non-fluorescent USDA122 and fluorescence-labeled SSBR45 also revealed that SSBR45 inhabits the intercellular spaces of healthy nodules. More unexpectedly, co-inoculation of eGFP-labeled USDA122 and DsRed-labeled SSBR45 (and vice versa) revealed the presence of USDA122 bacteria in both the symbiosomes of infected cells and in the apoplasts of healthy nodules. We then next inspected nodules formed after a mixed inoculation of differently-labeled USDA122, without SSBR45, and confirmed the inhabitation of the both populations of USDA122 in the intercellular spaces. In contrast, infected cells were occupied by single-labeled USDA122. We also observed Mesorhizobium loti in the intercellular spaces of active wild-type nodules of Lotus japonicus using transmission electron microscopy. Compatible intercellular rhizobia have been described during nodule formation of several legume species and in some mutants, but our evidence suggests that this type of colonization may occur much more commonly in leguminous root nodules.
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Affiliation(s)
- Shingo Hata
- Faculty of Agriculture, Ryukoku University, Otsu, Japan
| | - Risa Tsuda
- Faculty of Agriculture, Ryukoku University, Otsu, Japan
| | - Serina Kojima
- Faculty of Agriculture, Ryukoku University, Otsu, Japan
| | - Aiko Tanaka
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Hiroshi Kouchi
- Division of Arts and Sciences, International Christian University, Mitaka, Japan
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Hata S, Kojima S, Tsuda R, Kawajiri N, Kouchi H, Suzuki T, Uesaka K, Tanaka A. Characterization of photosynthetic Bradyrhizobium sp. strain SSBR45 isolated from the root nodules of Aeschynomene indica. PLANT SIGNALING & BEHAVIOR 2023; 18:2184907. [PMID: 36879507 PMCID: PMC10012927 DOI: 10.1080/15592324.2023.2184907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
We isolated a novel strain of Bradyrhizobium sp., SSBR45, from the nodulated roots of Aeschynomene indica and labeled it with Discosoma sp. red fluorescent protein (dsRED) or enhanced green fluorescent protein (eGFP) and determined its draft genomic sequence. The labeled SSBR45 stimulated the growth of A. indica markedly on a nitrogen-free medium, as observed by visualizing the fluorescent root nodules. The nodulated roots also exhibited high acetylene reduction activities. The SSBR45 genome included genes involved in nitrogen fixation, photosynthesis, and type IV secretion system; however, it did not consist of canonical nodABC genes and type III secretion system genes. SSBR45, a novel species of the genus Bradyrhizobium, consisted of an average nucleotide identity and average amino acid identity of 87% and 90%, respectively, with the closest strain B. oligotrophicum S58.
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Affiliation(s)
- Shingo Hata
- Faculty of Agriculture, Ryukoku University, Otsu, Japan
| | - Serina Kojima
- Faculty of Agriculture, Ryukoku University, Otsu, Japan
| | - Risa Tsuda
- Faculty of Agriculture, Ryukoku University, Otsu, Japan
| | | | - Hiroshi Kouchi
- Division of Arts and Sciences, International Christian University, Mitaka, Japan
| | - Takamasa Suzuki
- College of Bioscience and Biotechnology, Chubu University, Kasugai, Japan
| | - Kazuma Uesaka
- Center for Gene Research, Nagoya University, Nagoya, Japan
| | - Aiko Tanaka
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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Camuel A, Teulet A, Carcagno M, Haq F, Pacquit V, Gully D, Pervent M, Chaintreuil C, Fardoux J, Horta-Araujo N, Okazaki S, Ratu STN, Gueye F, Zilli J, Nouwen N, Arrighi JF, Luo H, Mergaert P, Deslandes L, Giraud E. Widespread Bradyrhizobium distribution of diverse Type III effectors that trigger legume nodulation in the absence of Nod factor. THE ISME JOURNAL 2023; 17:1416-1429. [PMID: 37355742 PMCID: PMC10432411 DOI: 10.1038/s41396-023-01458-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/08/2023] [Accepted: 06/13/2023] [Indexed: 06/26/2023]
Abstract
The establishment of the rhizobium-legume symbiosis is generally based on plant perception of Nod factors (NFs) synthesized by the bacteria. However, some Bradyrhizobium strains can nodulate certain legume species, such as Aeschynomene spp. or Glycine max, independently of NFs, and via two different processes that are distinguished by the necessity or not of a type III secretion system (T3SS). ErnA is the first known type III effector (T3E) triggering nodulation in Aeschynomene indica. In this study, a collection of 196 sequenced Bradyrhizobium strains was tested on A. indica. Only strains belonging to the photosynthetic supergroup can develop a NF-T3SS-independent symbiosis, while the ability to use a T3SS-dependent process is found in multiple supergroups. Of these, 14 strains lacking ernA were tested by mutagenesis to identify new T3Es triggering nodulation. We discovered a novel T3E, Sup3, a putative SUMO-protease without similarity to ErnA. Its mutation in Bradyrhizobium strains NAS96.2 and WSM1744 abolishes nodulation and its introduction in an ernA mutant of strain ORS3257 restores nodulation. Moreover, ectopic expression of sup3 in A. indica roots led to the formation of spontaneous nodules. We also report three other new T3Es, Ubi1, Ubi2 and Ubi3, which each contribute to the nodulation capacity of strain LMTR13. These T3Es have no homology to known proteins but share with ErnA three motifs necessary for ErnA activity. Together, our results highlight an unsuspected distribution and diversity of T3Es within the Bradyrhizobium genus that may contribute to their symbiotic efficiency by participating in triggering legume nodulation.
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Affiliation(s)
- Alicia Camuel
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Albin Teulet
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- University of Cambridge, Sainsbury Laboratory (SLCU), Cambridge, CB2 1LR, UK
| | - Mélanie Carcagno
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Fazal Haq
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Valérie Pacquit
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Djamel Gully
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Marjorie Pervent
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Clémence Chaintreuil
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Joël Fardoux
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
| | - Natasha Horta-Araujo
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Shin Okazaki
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Safirah Tasa Nerves Ratu
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Fatou Gueye
- Carrefour International, Bureau Régional Afrique de l'Ouest, Dakar, Sénégal
| | - Jerri Zilli
- Embrapa Agrobiologia, Bairro Ecologia, Seropedica, Rio de Janeiro, Brazil
| | - Nico Nouwen
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Jean-François Arrighi
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Haiwei Luo
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Peter Mergaert
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Laurent Deslandes
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Eric Giraud
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/Institut Agro/INRAE/Université de Montpellier/CIRAD, TA-A82/J- Campus de Baillarguet 34398, Montpellier cedex 5, France.
- PHIM Plant Health Institute, Université de Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France.
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9
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Avontuur JR, Wilken PM, Palmer M, Coetzee MPA, Stępkowski T, Venter SN, Steenkamp ET. Complex evolutionary history of photosynthesis in Bradyrhizobium. Microb Genom 2023; 9:001105. [PMID: 37676703 PMCID: PMC10569730 DOI: 10.1099/mgen.0.001105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 08/28/2023] [Indexed: 09/08/2023] Open
Abstract
Bradyrhizobium comprises a diverse group of bacteria with various lifestyles. Although best known for their nodule-based nitrogen-fixation in symbiosis with legumes, a select group of bradyrhizobia are also capable of photosynthesis. This ability seems to be rare among rhizobia, and its origin and evolution in these bacteria remain a subject of substantial debate. Therefore, our aim here was to investigate the distribution and evolution of photosynthesis in Bradyrhizobium using comparative genomics and representative genomes from closely related taxa in the families Nitrobacteraceae, Methylobacteriaceae, Boseaceae and Paracoccaceae . We identified photosynthesis gene clusters (PGCs) in 25 genomes belonging to three different Bradyrhizobium lineages, notably the so-called Photosynthetic, B. japonicum and B. elkanii supergroups. Also, two different PGC architectures were observed. One of these, PGC1, was present in genomes from the Photosynthetic supergroup and in three genomes from a species in the B. japonicum supergroup. The second cluster, PGC2, was also present in some strains from the B. japonicum supergroup, as well as in those from the B. elkanii supergroup. PGC2 was largely syntenic to the cluster found in Rhodopseudomonas palustris and Tardiphaga . Bayesian ancestral state reconstruction unambiguously showed that the ancestor of Bradyrhizobium lacked a PGC and that it was acquired horizontally by various lineages. Maximum-likelihood phylogenetic analyses of individual photosynthesis genes also suggested multiple acquisitions through horizontal gene transfer, followed by vertical inheritance and gene losses within the different lineages. Overall, our findings add to the existing body of knowledge on Bradyrhizobium ’s evolution and provide a meaningful basis from which to explore how these PGCs and the photosynthesis itself impact the physiology and ecology of these bacteria.
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Affiliation(s)
- Juanita R. Avontuur
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - P. Markus Wilken
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Marike Palmer
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Martin P. A. Coetzee
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Tomasz Stępkowski
- Department of Biochemistry and Microbiology, Institute of Biology, Warsaw University of Life Sciences (SGGW), Warszawa, Poland
| | - Stephanus N. Venter
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Emma T. Steenkamp
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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10
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Abstract
Plants associate with nitrogen-fixing bacteria to secure nitrogen, which is generally the most limiting nutrient for plant growth. Endosymbiotic nitrogen-fixing associations are widespread among diverse plant lineages, ranging from microalgae to angiosperms, and are primarily one of three types: cyanobacterial, actinorhizal or rhizobial. The large overlap in the signaling pathways and infection components of arbuscular mycorrhizal, actinorhizal and rhizobial symbioses reflects their evolutionary relatedness. These beneficial associations are influenced by environmental factors and other microorganisms in the rhizosphere. In this review, we summarize the diversity of nitrogen-fixing symbioses, key signal transduction pathways and colonization mechanisms relevant to such interactions, and compare and contrast these interactions with arbuscular mycorrhizal associations from an evolutionary standpoint. Additionally, we highlight recent studies on environmental factors regulating nitrogen-fixing symbioses to provide insights into the adaptation of symbiotic plants to complex environments.
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Affiliation(s)
- Peng Xu
- National key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Ertao Wang
- National key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; New Cornerstone Science Laboratory, Shenzhen 518054, China.
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11
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Bopape FL, Chiulele RM, Shonhai A, Gwata ET. The Genome of a Pigeonpea Compatible Rhizobial Strain '10ap3' Appears to Lack Common Nodulation Genes. Genes (Basel) 2023; 14:1084. [PMID: 37239443 PMCID: PMC10217799 DOI: 10.3390/genes14051084] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/10/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023] Open
Abstract
The symbiotic fixation of atmospheric nitrogen (N) in root nodules of tropical legumes such as pigeonpea (Cajanus cajan) is a complex process, which is regulated by multiple genetic factors at the host plant genotype microsymbiont interface. The process involves multiple genes with various modes of action and is accomplished only when both organisms are compatible. Therefore, it is necessary to develop tools for the genetic manipulation of the host or bacterium towards improving N fixation. In this study, we sequenced the genome of a robust rhizobial strain, Rhizobium tropici '10ap3' that was compatible with pigeonpea, and we determined its genome size. The genome consisted of a large circular chromosome (6,297,373 bp) and contained 6013 genes of which 99.13% were coding sequences. However only 5833 of the genes were associated with proteins that could be assigned to specific functions. The genes for nitrogen, phosphorus and iron metabolism, stress response and the adenosine monophosphate nucleoside for purine conversion were present in the genome. However, the genome contained no common nod genes, suggesting that an alternative pathway involving a purine derivative was involved in the symbiotic association with pigeonpea.
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Affiliation(s)
- Francina L. Bopape
- Agricultural Research Council, Plant Health and Protection (ARC-PHP), Private Bag X134, Pretoria 0121, South Africa
- Department of Plant and Soil Sciences, Faculty of Science, Engineering and Agriculture, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa
| | - Rogerio M. Chiulele
- Centre of Excellence in Agri-Food Systems and Nutrition, Eduardo Mondlane University, 5th Floor, Rectory Building, 25th June Square, Maputo 1100, Mozambique;
- Faculty of Agronomy and Forestry Engineering, Eduardo Mondlane University, Julius Nyerere Avenue, Maputo 1100, Mozambique
| | - Addmore Shonhai
- Department of Biochemistry and Microbiology, Faculty of Science, Engineering and Agriculture, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa
| | - Eastonce T. Gwata
- Department of Plant and Soil Sciences, Faculty of Science, Engineering and Agriculture, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa
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12
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Tehrani N, Mitra RM. Plant pathogens and symbionts target the plant nucleus. Curr Opin Microbiol 2023; 72:102284. [PMID: 36868049 DOI: 10.1016/j.mib.2023.102284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/20/2023] [Accepted: 01/24/2023] [Indexed: 03/05/2023]
Abstract
In plant-microbe interactions, symbionts and pathogens live within plants and attempt to avoid triggering plant defense responses. In order to do so, these microbes have evolved multiple mechanisms that target components of the plant cell nucleus. Rhizobia-induced symbiotic signaling requires the function of specific legume nucleoporins within the nuclear pore complex. Symbiont and pathogen effectors harbor nuclear localization sequences that facilitate movement across nuclear pores, allowing these proteins to target transcription factors that function in defense. Oomycete pathogens introduce proteins that interact with plant pre-mRNA splicing components in order to alter host splicing of defense-related transcripts. Together, these functions indicate that the nucleus is an active site of symbiotic and pathogenic functioning in plant-microbe interactions.
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13
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Guo K, Yang J, Yu N, Luo L, Wang E. Biological nitrogen fixation in cereal crops: Progress, strategies, and perspectives. PLANT COMMUNICATIONS 2023; 4:100499. [PMID: 36447432 PMCID: PMC10030364 DOI: 10.1016/j.xplc.2022.100499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/07/2022] [Accepted: 11/28/2022] [Indexed: 05/04/2023]
Abstract
Nitrogen is abundant in the atmosphere but is generally the most limiting nutrient for plants. The inability of many crop plants, such as cereals, to directly utilize freely available atmospheric nitrogen gas means that their growth and production often rely heavily on the application of chemical fertilizers, which leads to greenhouse gas emissions and the eutrophication of water. By contrast, legumes gain access to nitrogen through symbiotic association with rhizobia. These bacteria convert nitrogen gas into biologically available ammonia in nodules through a process termed symbiotic biological nitrogen fixation, which plays a decisive role in ecosystem functioning. Engineering cereal crops that can fix nitrogen like legumes or associate with nitrogen-fixing microbiomes could help to avoid the problems caused by the overuse of synthetic nitrogen fertilizer. With the development of synthetic biology, various efforts have been undertaken with the aim of creating so-called "N-self-fertilizing" crops capable of performing autonomous nitrogen fixation to avoid the need for chemical fertilizers. In this review, we briefly summarize the history and current status of engineering N-self-fertilizing crops. We also propose several potential biotechnological approaches for incorporating biological nitrogen fixation capacity into non-legume plants.
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Affiliation(s)
- Kaiyan Guo
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jun Yang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Nan Yu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China.
| | - Li Luo
- School of Life Sciences, Shanghai Key Laboratory of Bioenergy Crops, Shanghai University, Shanghai 200444, China.
| | - Ertao Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
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14
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Legumes Regulate Symbiosis with Rhizobia via Their Innate Immune System. Int J Mol Sci 2023; 24:ijms24032800. [PMID: 36769110 PMCID: PMC9917363 DOI: 10.3390/ijms24032800] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/18/2023] [Accepted: 01/18/2023] [Indexed: 02/05/2023] Open
Abstract
Plant roots are constantly exposed to a diverse microbiota of pathogens and mutualistic partners. The host's immune system is an essential component for its survival, enabling it to monitor nearby microbes for potential threats and respond with a defence response when required. Current research suggests that the plant immune system has also been employed in the legume-rhizobia symbiosis as a means of monitoring different rhizobia strains and that successful rhizobia have evolved to overcome this system to infect the roots and initiate nodulation. With clear implications for host-specificity, the immune system has the potential to be an important target for engineering versatile crops for effective nodulation in the field. However, current knowledge of the interacting components governing this pathway is limited, and further research is required to build on what is currently known to improve our understanding. This review provides a general overview of the plant immune system's role in nodulation. With a focus on the cycles of microbe-associated molecular pattern-triggered immunity (MTI) and effector-triggered immunity (ETI), we highlight key molecular players and recent findings while addressing the current knowledge gaps in this area.
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15
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Adaptive Evolution of Rhizobial Symbiosis beyond Horizontal Gene Transfer: From Genome Innovation to Regulation Reconstruction. Genes (Basel) 2023; 14:genes14020274. [PMID: 36833201 PMCID: PMC9957244 DOI: 10.3390/genes14020274] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/22/2023] Open
Abstract
There are ubiquitous variations in symbiotic performance of different rhizobial strains associated with the same legume host in agricultural practices. This is due to polymorphisms of symbiosis genes and/or largely unexplored variations in integration efficiency of symbiotic function. Here, we reviewed cumulative evidence on integration mechanisms of symbiosis genes. Experimental evolution, in concert with reverse genetic studies based on pangenomics, suggests that gain of the same circuit of key symbiosis genes through horizontal gene transfer is necessary but sometimes insufficient for bacteria to establish an effective symbiosis with legumes. An intact genomic background of the recipient may not support the proper expression or functioning of newly acquired key symbiosis genes. Further adaptive evolution, through genome innovation and reconstruction of regulation networks, may confer the recipient of nascent nodulation and nitrogen fixation ability. Other accessory genes, either co-transferred with key symbiosis genes or stochastically transferred, may provide the recipient with additional adaptability in ever-fluctuating host and soil niches. Successful integrations of these accessory genes with the rewired core network, regarding both symbiotic and edaphic fitness, can optimize symbiotic efficiency in various natural and agricultural ecosystems. This progress also sheds light on the development of elite rhizobial inoculants using synthetic biology procedures.
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16
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Garcia K, Cloghessy K, Cooney DR, Shelley B, Chakraborty S, Kafle A, Busidan A, Sonawala U, Collier R, Jayaraman D, Ané JM, Pilot G. The putative transporter MtUMAMIT14 participates in nodule formation in Medicago truncatula. Sci Rep 2023; 13:804. [PMID: 36646812 PMCID: PMC9842706 DOI: 10.1038/s41598-023-28160-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/13/2023] [Indexed: 01/17/2023] Open
Abstract
Transport systems are crucial in many plant processes, including plant-microbe interactions. Nodule formation and function in legumes involve the expression and regulation of multiple transport proteins, and many are still uncharacterized, particularly for nitrogen transport. Amino acids originating from the nitrogen-fixing process are an essential form of nitrogen for legumes. This work evaluates the role of MtN21 (henceforth MtUMAMIT14), a putative transport system from the MtN21/EamA-like/UMAMIT family, in nodule formation and nitrogen fixation in Medicago truncatula. To dissect this transporter's role, we assessed the expression of MtUMAMIT14 using GUS staining, localized the corresponding protein in M. truncatula root and tobacco leaf cells, and investigated two independent MtUMAMIT14 mutant lines. Our results indicate that MtUMAMIT14 is localized in endosomal structures and is expressed in both the infection zone and interzone of nodules. Comparison of mutant and wild-type M. truncatula indicates MtUMAMIT14, the expression of which is dependent on the presence of NIN, DNF1, and DNF2, plays a role in nodule formation and nitrogen-fixation. While the function of the transporter is still unclear, our results connect root nodule nitrogen fixation in legumes with the UMAMIT family.
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Affiliation(s)
- Kevin Garcia
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC, 27695-7619, USA.
| | - Kaylee Cloghessy
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA.,Department of Biological Sciences, The University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Danielle R Cooney
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC, 27695-7619, USA
| | - Brett Shelley
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, 24060, USA
| | - Sanhita Chakraborty
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Arjun Kafle
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC, 27695-7619, USA
| | - Aymeric Busidan
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, 24060, USA
| | - Unnati Sonawala
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, 24060, USA
| | - Ray Collier
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA.,Molecular Technologies Department, Wisconsin Crop Innovation Center, University of Wisconsin-Madison, Madison, WI, 53562, USA
| | | | - Jean-Michel Ané
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA.,Department of Agronomy, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Guillaume Pilot
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, 24060, USA
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17
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Amaral MB, Dos Santos Lopes T, Feder CB, Ribeiro TG, Pacheco RS, Teixeira TN, de Castro Monteiro E, Ramalho IO, de O Macedo R, Boddey RM, Zilli JE, Alves BJR. Bradyrhizobium occurrence in nodules of perennial horsegram. Braz J Microbiol 2022; 53:2065-2075. [PMID: 36074250 PMCID: PMC9679115 DOI: 10.1007/s42770-022-00821-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 08/30/2022] [Indexed: 01/13/2023] Open
Abstract
The introduction of a forage legume into a tropical pasture should decrease the need for N fertilizer, provided biological N2 fixation (BNF) contributes enough to compensate for exported N. Macrotyloma axillare (perennial horsegram) is a suitable legume for composing mixed pastures, and our hypothesis is that the isolation of indigenous rhizobia from roots and rhizosphere is the way of achieving an efficient inoculant to maximize BNF to the legume. Nodules and rhizosphere soil taken from M. axillare grown in a mixed pasture with palisade grass were sampled and used in a trap host assay using Leonard jars containing a mixture of vermiculite and sand. A total of ten bacteria were initially isolated using this technique. The isolates were then used in two experiments to evaluate the inoculation responses on the perennial horsegram in greenhouse conditions to which nodulation, plant growth, and shoot N accumulation were measured. Phylogenetic analyses based on 16S rRNA and recA placed all strains within genus Bradyrhizobium, some of them not previously described. The best strain provided more than 120 nodules and more than 65 mg of nodules per plant. Strain BR14182 was considered the most promising given the high dry matter and N accumulation in plant shoots. This study provides the first analysis of Bradyrhizobium diversity nodulating M. axillare in Brazil and provided evidence of the role of inoculation in incrementing the plant-rhizobium symbiosis in a forage legume.
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Affiliation(s)
- Mayan Blanc Amaral
- Universidade Federal Rural Do Rio de Janeiro, BR 465, km 07, 23897-000, Seropédica, RJ, Brazil.
| | | | - Caroline Bueno Feder
- Universidade Federal Rural Do Rio de Janeiro, BR 465, km 07, 23897-000, Seropédica, RJ, Brazil
| | | | | | - Thiago Neves Teixeira
- Departamento de Zootecnia, Universidade Federal de Viçosa, Purdue Avenue, 53, 36570-900, Viçosa, MG, Brazil
| | | | - Israel Oliveira Ramalho
- Universidade Federal Rural Do Rio de Janeiro, BR 465, km 07, 23897-000, Seropédica, RJ, Brazil
| | - Robert de O Macedo
- Universidade Federal Rural Do Rio de Janeiro, BR 465, km 07, 23897-000, Seropédica, RJ, Brazil
| | - Robert M Boddey
- Embrapa Agrobiologia, BR 465, km 07, 23891-000, Seropédica, RJ, Brazil
| | - Jerri Edson Zilli
- Embrapa Agrobiologia, BR 465, km 07, 23891-000, Seropédica, RJ, Brazil
| | - Bruno J R Alves
- Embrapa Agrobiologia, BR 465, km 07, 23891-000, Seropédica, RJ, Brazil
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18
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Ghantasala S, Roy Choudhury S. Nod factor perception: an integrative view of molecular communication during legume symbiosis. PLANT MOLECULAR BIOLOGY 2022; 110:485-509. [PMID: 36040570 DOI: 10.1007/s11103-022-01307-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
Compatible interaction between rhizobial Nod factors and host receptors enables initial recognition and signaling events during legume-rhizobia symbiosis. Molecular communication is a new paradigm of information relay, which uses chemical signals or molecules as dialogues for communication and has been witnessed in prokaryotes, plants as well as in animal kingdom. Understanding this fascinating relay of signals between plants and rhizobia during the establishment of a synergistic relationship for biological nitrogen fixation represents one of the hotspots in plant biology research. Predominantly, their interaction is initiated by flavonoids exuding from plant roots, which provokes changes in the expression profile of rhizobial genes. Compatible interactions promote the secretion of Nod factors (NFs) from rhizobia, which are recognised by cognate host receptors. Perception of NFs by host receptors initiates the symbiosis and ultimately leads to the accommodation of rhizobia within root nodules via a series of mutual exchange of signals. This review elucidates the bacterial and plant perspectives during the early stages of symbiosis, explicitly emphasizing the significance of NFs and their cognate NF receptors.
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Affiliation(s)
- Swathi Ghantasala
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh, 517507, India
| | - Swarup Roy Choudhury
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh, 517507, India.
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19
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Li RJ, Zhang CX, Fan SY, Wang YH, Wen J, Mysore KS, Xie ZP, Staehelin C. The Medicago truncatula hydrolase MtCHIT5b degrades Nod factors of Sinorhizobium meliloti and cooperates with MtNFH1 to regulate the nodule symbiosis. FRONTIERS IN PLANT SCIENCE 2022; 13:1034230. [PMID: 36466271 PMCID: PMC9712974 DOI: 10.3389/fpls.2022.1034230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/25/2022] [Indexed: 06/17/2023]
Abstract
Nod factors secreted by nitrogen-fixing rhizobia are lipo-chitooligosaccharidic signals required for establishment of the nodule symbiosis with legumes. In Medicago truncatula, the Nod factor hydrolase 1 (MtNFH1) was found to cleave Nod factors of Sinorhizobium meliloti. Here, we report that the class V chitinase MtCHIT5b of M. truncatula expressed in Escherichia coli can release lipodisaccharides from Nod factors. Analysis of M. truncatula mutant plants indicated that MtCHIT5b, together with MtNFH1, degrades S. meliloti Nod factors in the rhizosphere. MtCHIT5b expression was induced by treatment of roots with purified Nod factors or inoculation with rhizobia. MtCHIT5b with a fluorescent tag was detected in the infection pocket of root hairs. Nodulation of a MtCHIT5b knockout mutant was not significantly altered whereas overexpression of MtCHIT5b resulted in fewer nodules. Reduced nodulation was observed when MtCHIT5b and MtNFH1 were simultaneously silenced in RNA interference experiments. Overall, this study shows that nodule formation of M. truncatula is regulated by a second Nod factor cleaving hydrolase in addition to MtNFH1.
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Affiliation(s)
- Ru-Jie Li
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Chun-Xiao Zhang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Sheng-Yao Fan
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yi-Han Wang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jiangqi Wen
- Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Kirankumar S. Mysore
- Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhi-Ping Xie
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Christian Staehelin
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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20
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Quilbé J, Nouwen N, Pervent M, Guyonnet R, Cullimore J, Gressent F, Araújo NH, Gully D, Klopp C, Giraud E, Arrighi JF. A mutant-based analysis of the establishment of Nod-independent symbiosis in the legume Aeschynomene evenia. PLANT PHYSIOLOGY 2022; 190:1400-1417. [PMID: 35876558 PMCID: PMC9516736 DOI: 10.1093/plphys/kiac325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/10/2022] [Indexed: 06/15/2023]
Abstract
Intensive research on nitrogen-fixing symbiosis in two model legumes has uncovered the molecular mechanisms, whereby rhizobial Nod factors activate a plant symbiotic signaling pathway that controls infection and nodule organogenesis. In contrast, the so-called Nod-independent symbiosis found between Aeschynomene evenia and photosynthetic bradyrhizobia, which does not involve Nod factor recognition nor infection thread formation, is less well known. To gain knowledge on how Nod-independent symbiosis is established, we conducted a phenotypic and molecular characterization of A. evenia lines carrying mutations in different nodulation genes. Besides investigating the effect of the mutations on rhizobial symbiosis, we examined their consequences on mycorrhizal symbiosis and in nonsymbiotic conditions. Analyzing allelic mutant series for AePOLLUX, Ca2+/calmodulin dependent kinase, AeCYCLOPS, nodulation signaling pathway 2 (AeNSP2), and nodule inception demonstrated that these genes intervene at several stages of intercellular infection and during bacterial accommodation. We provide evidence that AeNSP2 has an additional nitrogen-dependent regulatory function in the formation of axillary root hairs at lateral root bases, which are rhizobia-colonized infection sites. Our investigation of the recently discovered symbiotic actor cysteine-rich receptor-like kinase specified that it is not involved in mycorrhization; however, it is essential for both symbiotic signaling and early infection during nodulation. These findings provide important insights on the modus operandi of Nod-independent symbiosis and contribute to the general understanding of how rhizobial-legume symbioses are established by complementing the information acquired in model legumes.
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Affiliation(s)
| | | | | | - Rémi Guyonnet
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRAE/UM/CIRAD, TA-A82/J-Campus de Baillarguet, Montpellier 34398, France
| | - Julie Cullimore
- Laboratory of Plant-Microbe Interactions and Environment (LIPME), University Toulouse III, INRAE, CNRS, Castanet-Tolosan, France
| | - Frédéric Gressent
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRAE/UM/CIRAD, TA-A82/J-Campus de Baillarguet, Montpellier 34398, France
- IRD, Plant Health Institute of Montpellier (PHIM), UMR IRD/SupAgro/INRAE/UM/CIRAD, TA-A82/J – Campus de Baillarguet, Montpellier 34398, France
| | - Natasha Horta Araújo
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRAE/UM/CIRAD, TA-A82/J-Campus de Baillarguet, Montpellier 34398, France
- IRD, Plant Health Institute of Montpellier (PHIM), UMR IRD/SupAgro/INRAE/UM/CIRAD, TA-A82/J – Campus de Baillarguet, Montpellier 34398, France
| | - Djamel Gully
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRAE/UM/CIRAD, TA-A82/J-Campus de Baillarguet, Montpellier 34398, France
- IRD, Plant Health Institute of Montpellier (PHIM), UMR IRD/SupAgro/INRAE/UM/CIRAD, TA-A82/J – Campus de Baillarguet, Montpellier 34398, France
| | - Christophe Klopp
- Plateforme Bioinformatique Genotoul, BioinfoMics, UR875 Biométrie et Intelligence Artificielle, INRAE, Castanet-Tolosan, France
| | - Eric Giraud
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRAE/UM/CIRAD, TA-A82/J-Campus de Baillarguet, Montpellier 34398, France
- IRD, Plant Health Institute of Montpellier (PHIM), UMR IRD/SupAgro/INRAE/UM/CIRAD, TA-A82/J – Campus de Baillarguet, Montpellier 34398, France
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Jiménez-Guerrero I, Medina C, Vinardell JM, Ollero FJ, López-Baena FJ. The Rhizobial Type 3 Secretion System: The Dr. Jekyll and Mr. Hyde in the Rhizobium–Legume Symbiosis. Int J Mol Sci 2022; 23:ijms231911089. [PMID: 36232385 PMCID: PMC9569860 DOI: 10.3390/ijms231911089] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/08/2022] [Accepted: 09/14/2022] [Indexed: 01/14/2023] Open
Abstract
Rhizobia are soil bacteria that can establish a symbiotic association with legumes. As a result, plant nodules are formed on the roots of the host plants where rhizobia differentiate to bacteroids capable of fixing atmospheric nitrogen into ammonia. This ammonia is transferred to the plant in exchange of a carbon source and an appropriate environment for bacterial survival. This process is subjected to a tight regulation with several checkpoints to allow the progression of the infection or its restriction. The type 3 secretion system (T3SS) is a secretory system that injects proteins, called effectors (T3E), directly into the cytoplasm of the host cell, altering host pathways or suppressing host defense responses. This secretion system is not present in all rhizobia but its role in symbiosis is crucial for some symbiotic associations, showing two possible faces as Dr. Jekyll and Mr. Hyde: it can be completely necessary for the formation of nodules, or it can block nodulation in different legume species/cultivars. In this review, we compile all the information currently available about the effects of different rhizobial effectors on plant symbiotic phenotypes. These phenotypes are diverse and highlight the importance of the T3SS in certain rhizobium–legume symbioses.
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22
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Sun M, Liu X, Shi K, Peng F, Xiao Y. Effects of Root Zone Aeration on Soil Microbes Species in a Peach Tree Rhizosphere and Root Growth. Microorganisms 2022; 10:1879. [PMID: 36296156 PMCID: PMC9611397 DOI: 10.3390/microorganisms10101879] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/07/2022] [Accepted: 09/16/2022] [Indexed: 09/16/2023] Open
Abstract
The oxygen content in the root zone considerably affects the growth and development of peach trees. However, few studies have been conducted on the effects of the oxygen content in the root zones of peach trees on soil microbes and root growth. Four-year-old Ruiguang 33/Prunus persica (L.) Batsch trees were used to study the effects of root-zone aeration on soil microbes in a peach orchard, as well as on the soil nutrient contents, peach tree root systems, and plant potassium-to-nitrogen ratios. The results showed that the root-zone aeration substantially increased the soil oxygen content in the root zone and changed the soil microbial community structure. Compared with the control, the relative abundances of soil nitrogen-fixing microorganisms (Beta proteobacteria and Bradyrhizobium elkanii) and potassium-solubilizing microorganisms (Bacillus circulans) under the root-zone aeration conditions were greatly enhanced. Root-zone aeration increased the soil's alkaline nitrogen content, available potassium content, and organic matter content, as well as the number and thickness of new white roots of peach trees, and root activity was increased significantly. At the same time, root-zone aeration changed the relative contents of total potassium and total nitrogen in the plants and considerably increased the potassium-nitrogen ratio in the shoots. The results indicate that aeration in the root zone can change the soil microbial community structure, increase the abundances of nitrogen-fixing and potassium-solubilizing microorganisms, and increase the plant potassium-to-nitrogen ratio, which are conducive to peach fruit quality.
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Affiliation(s)
| | | | | | - Futian Peng
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an 271018, China
| | - Yuansong Xiao
- State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an 271018, China
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23
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Shang JY, Zhang P, Jia YW, Lu YN, Wu Y, Ji S, Chen L, Wang ET, Chen WX, Sui XH. Coordinated regulation of symbiotic adaptation by NodD proteins and NolA in the type I peanut bradyrhizobial strain Bradyrhizobium zhanjiangense CCBAU51778. Microbiol Res 2022; 265:127188. [PMID: 36152611 DOI: 10.1016/j.micres.2022.127188] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/27/2022] [Accepted: 09/06/2022] [Indexed: 10/14/2022]
Abstract
Type I peanut bradyrhizobial strains can establish efficient symbiosis in contrast to symbiotic incompatibility induced by type II strains with mung bean. The notable distinction in the two kinds of key symbiosis-related regulators nolA and nodD close to the nodABCSUIJ operon region between these two types of peanut bradyrhizobia was found. Therefore, we determined whether NolA and NodD proteins regulate the symbiotic adaptations of type I strains to different hosts. We found that NodD1-NolA synergistically regulated the symbiosis between the type I strain Bradyrhizobium zhanjiangense CCBAU51778 and mung bean, and NodD1-NodD2 jointly regulated nodulation ability. In contrast, NodD1-NolA coordinately regulated nodulation ability in the CCBAU51778-peanut symbiosis. Meanwhile, NodD1 and NolA collectively contributes to competitive nodule colonization of CCBAU51778 on both hosts. The Fucosylated Nod factors and intact type 3 secretion system (T3SS), rather than extra nodD2 and full-length nolA, were critical for effective symbiosis with mung bean. Unexpectedly, T3SS-related genes were activated by NodD2 but not NodD1. Compared to NodD1 and NodD2, NolA predominantly inhibits exopolysaccharide production by promoting exoR expression. Importantly, this is the first report that NolA regulates rhizobial T3SS-related genes. The coordinated regulation and integration of different gene networks to fine-tune the expression of symbiosis-related genes and other accessory genes by NodD1-NolA might be required for CCBAU51778 to efficiently nodulate peanut. This study shed new light on our understanding of the regulatory roles of NolA and NodD proteins in symbiotic adaptation, highlighting the sophisticated gene networks dominated by NodD1-NolA.
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Affiliation(s)
- Jiao Ying Shang
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Pan Zhang
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China; CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Yu Wen Jia
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yi Ning Lu
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yue Wu
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Shuang Ji
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - La Chen
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - En Tao Wang
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México, D. F. 11340, Mexico
| | - Wen Xin Chen
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xin Hua Sui
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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24
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Identification and Validation of Reference Genes for Expression Analysis in Nitrogen-Fixing Bacteria under Environmental Stress. Life (Basel) 2022; 12:life12091379. [PMID: 36143415 PMCID: PMC9505014 DOI: 10.3390/life12091379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/15/2022] [Accepted: 09/02/2022] [Indexed: 11/17/2022] Open
Abstract
Reference genes, also referred to as housekeeping genes (HKGs), play an important role in gene expression analysis by serving as an internal control. These HKGs are usually involved in basic cellular functions and their expression should remain at relatively constant levels. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) has been used to measure gene expression. Since the normalization of gene expression data depends on baseline expression of HKGs, it is important to identify and verify true HKGs for the qRT-PCR analysis. The goal of this study is to identify and confirm HKGs in Bradyrhizobium diazoefficiens, a nitrogen fixing bacterium which forms a symbiotic relationship with soybean. By revealing such HKGs, the normalization of gene expression would be more robust, reliable, and consistent. Here, we analyzed previous gene expression data for B. diazoefficiens under multiple environmental conditions. As a result, we identified seven constitutively expressed genes among 8453 genes across all conditions. Their fold-change values were within a range of −1.25-fold < x < 1.25-fold. We adopted GeNorm, NormFinder, and comparative ∆Ct methods to rank the seven candidate genes based on their expression stability. To validate these potential HKGs, we measured their expression in various experimental conditions, such as heat, pH, and heavy metal stress. The HKGs that were found in B. diazoefficiens were also applied in closely related species by identifying their homologs.
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Mathesius U. Are legumes different? Origins and consequences of evolving nitrogen fixing symbioses. JOURNAL OF PLANT PHYSIOLOGY 2022; 276:153765. [PMID: 35952452 DOI: 10.1016/j.jplph.2022.153765] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/01/2022] [Accepted: 07/03/2022] [Indexed: 05/14/2023]
Abstract
Nitrogen fixing symbioses between plants and bacteria are ancient and, while not numerous, are formed in diverse lineages of plants ranging from microalgae to angiosperms. One symbiosis stands out as the most widespread one is that between legumes and rhizobia, leading to the formation of nitrogen-fixing nodules. The legume family is one of the largest and most diverse group of plants and legumes have been used by humans since the beginning of agriculture, both as high nitrogen food, as well as pastures and rotation crops. One open question is whether their ability to form a nitrogen-fixing symbiosis has contributed to legumes' success, and whether legumes have any unique characteristics that have made them more diverse and widespread than other groups of plants. This review examines the evolutionary journey that has led to the diversification of legumes, in particular its nitrogen-fixing symbiosis, and asks four questions to investigate which legume traits might have contributed to their success: 1. In what ways do legumes differ from other plant groups that have evolved nitrogen-fixing symbioses? In order to answer this question, the characteristics of the symbioses, and efficiencies of nitrogen fixation are compared between different groups of nitrogen fixing plants. 2. Could certain unique features of legumes be a reason for their success? This section examines the manifestations and possible benefits of a nitrogen-rich 'lifestyle' in legumes. 3. If nitrogen fixation was a reason for such a success, why have some species lost the symbiosis? Formation of symbioses has trade-offs, and while these are less well known for non-legumes, there are known energetic and ecological reasons for loss of symbiotic potential in legumes. 4. What can we learn from the unique traits of legumes for future crop improvements? While exploiting some of the physiological properties of legumes could be used to improve legume breeding, our increasing molecular understanding of the essential regulators of root nodule symbioses raise hope of creating new nitrogen fixing symbioses in other crop species.
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Affiliation(s)
- Ulrike Mathesius
- Division of Plant Sciences, Research School of Biology, The Australian National University, 134 Linnaeus Way, Canberra, ACT, 2601, Australia.
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26
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Total Synthesis of the Methyl Glycoside of Bradyrhizose via Intramolecular Pinacol Coupling. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.154060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Klepa MS, Helene LCF, O´Hara G, Hungria M. Bradyrhizobium cenepequi sp. nov., Bradyrhizobium semiaridum sp. nov., Bradyrhizobium hereditatis sp. nov. and Bradyrhizobium australafricanum sp. nov., symbionts of different leguminous plants of Western Australia and South Africa and definition of three novel symbiovars. Int J Syst Evol Microbiol 2022; 72. [DOI: 10.1099/ijsem.0.005446] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bradyrhizobium
is a heterogeneous bacterial genus capable of establishing symbiotic associations with a broad range of legume hosts, including species of economic and environmental importance. This study was focused on the taxonomic and symbiovar definition of four strains – CNPSo 4026T, WSM 1704T, WSM 1738T and WSM 4400T – previously isolated from nodules of legumes in Western Australia and South Africa. The 16S rRNA gene phylogenetic tree allocated the strains to the
Bradyrhizobium elkanii
supergroup. The multilocus sequence analysis (MLSA) with partial sequences of six housekeeping genes – atpD, dnaK, glnII, gyrB, recA and rpoB – did not cluster the strains under study as conspecific to any described
Bradyrhizobium
species. Average nucleotide identity and digital DNA–DNA hybridization values were calculated for the four strains of this study and the closest species according to the MLSA phylogeny with the highest values being 95.46 and 62.20 %, respectively; therefore, both being lower than the species delineation cut-off values. The nodC and nifH phylogenies included strains WSM 1738T and WSM 4400T in the symbiovars retamae and vignae respectively, and also allowed the definition of three new symbiovars, sv. cenepequi, sv. glycinis, and sv. cajani. Analysis of morphophysiological characterization reinforced the identification of four novel proposed
Bradyrhizobium
species that are accordingly named as follows: Bradyrhizobium cenepequi sp. nov. (CNPSo 4026T=WSM 4798T=LMG 31653T), isolated from Vigna unguiculata; Bradyrhizobium semiaridum sp. nov. (WSM 1704T=CNPSo 4028T=LMG 31654T), isolated from Tephrosia gardneri; Bradyrhizobium hereditatis sp. nov. (WSM 1738T=CNPSo 4025T=LMG 31652T), isolated from Indigofera sp.; and Bradyrhizobium australafricanum sp. nov. (WSM 4400T=CNPSo 4015T=LMG 31648T) isolated from Glycine sp.
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Affiliation(s)
- Milena Serenato Klepa
- Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, SBN, Quadra 2, Bloco L, Lote 06, Edifício Capes, 70.040-020, Brasília, Distrito Federal, Brazil
- Department of Microbiology, Universidade Estadual de Londrina, C.P. 10011, 86057-970, Londrina, Paraná, Brazil
- Embrapa Soja, C.P. 231, 86001-970, Londrina, Paraná, Brazil
| | - Luisa Caroline Ferraz Helene
- Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, SBN, Quadra 2, Bloco L, Lote 06, Edifício Capes, 70.040-020, Brasília, Distrito Federal, Brazil
- Embrapa Soja, C.P. 231, 86001-970, Londrina, Paraná, Brazil
| | - Graham O´Hara
- Centre for Rhizobium Studies (CRS), Murdoch University 90 South St. Murdoch, WA, Australia
| | - Mariangela Hungria
- Department of Microbiology, Universidade Estadual de Londrina, C.P. 10011, 86057-970, Londrina, Paraná, Brazil
- Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, SBN, Quadra 2, Bloco L, Lote 06, Edifício Capes, 70.040-020, Brasília, Distrito Federal, Brazil
- Embrapa Soja, C.P. 231, 86001-970, Londrina, Paraná, Brazil
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28
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Huo H, Zong L, Liu Y, Chen W, Chen J, Wei G. Rhizobial HmuS pSym as a heme-binding factor is required for optimal symbiosis between Mesorhizobium amorphae CCNWGS0123 and Robinia pseudoacacia. PLANT, CELL & ENVIRONMENT 2022; 45:2191-2210. [PMID: 35419804 DOI: 10.1111/pce.14335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 01/15/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Nitrogen-fixing root nodules are formed by symbiotic association of legume hosts with rhizobia in nitrogen-deprived soils. Successful symbiosis is regulated by signals from both legume hosts and their rhizobial partners. HmuS is a heme degrading factor widely distributed in bacteria, but little is known about the role of rhizobial hmuS in symbiosis with legumes. Here, we found that inactivation of hmuSpSym in the symbiotic plasmid of Mesorhizobium amorphae CCNWGS0123 disrupted rhizobial infection, primordium formation, and nitrogen fixation in symbiosis with Robinia pseudoacacia. Although there was no difference in bacteroids differentiation, infected plant cells were shrunken and bacteroids were disintegrated in nodules of plants infected by the ΔhmuSpSym mutant strain. The balance of defence reaction was also impaired in ΔhmuSpSym strain-infected root nodules. hmuSpSym was strongly expressed in the nitrogen-fixation zone of mature nodules. Furthermore, the HmuSpSym protein could bind to heme but not degrade it. Inactivation of hmuSpSym led to significantly decreased expression levels of oxygen-sensing related genes in nodules. In summary, hmuSpSym of M. amorphae CCNWGS0123 plays an essential role in nodule development and maintenance of bacteroid survival within R. pseudoacacia cells, possibly through heme-binding in symbiosis.
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Affiliation(s)
- Haibo Huo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, China
| | - Le Zong
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, China
| | - Yao Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, China
| | - Wenfeng Chen
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences and Rhizobium Research Center, Ministry of Agriculture Key Laboratory of Soil Microbiology, China Agricultural University, Beijing, China
| | - Juan Chen
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi, China
| | - Gehong Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, China
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29
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Quilbé J, Montiel J, Arrighi JF, Stougaard J. Molecular Mechanisms of Intercellular Rhizobial Infection: Novel Findings of an Ancient Process. FRONTIERS IN PLANT SCIENCE 2022; 13:922982. [PMID: 35812902 PMCID: PMC9260380 DOI: 10.3389/fpls.2022.922982] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Establishment of the root-nodule symbiosis in legumes involves rhizobial infection of nodule primordia in the root cortex that is dependent on rhizobia crossing the root epidermal barrier. Two mechanisms have been described: either through root hair infection threads or through the intercellular passage of bacteria. Among the legume genera investigated, around 75% use root hair entry and around 25% the intercellular entry mode. Root-hair infection thread-mediated infection has been extensively studied in the model legumes Medicago truncatula and Lotus japonicus. In contrast, the molecular circuit recruited during intercellular infection, which is presumably an ancient and simpler pathway, remains poorly known. In recent years, important discoveries have been made to better understand the transcriptome response and the genetic components involved in legumes with obligate (Aeschynomene and Arachis spp.) and conditional (Lotus and Sesbania spp.) intercellular rhizobial infections. This review addresses these novel findings and briefly considers possible future research to shed light on the molecular players that orchestrate intercellular infection in legumes.
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Affiliation(s)
- Johan Quilbé
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jesús Montiel
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Centre for Genomic Sciences, National Autonomous University of Mexico (UNAM), Cuernavaca, Mexico
| | - Jean-François Arrighi
- IRD, Plant Health Institute of Montpellier (PHIM), UMR IRD/SupAgro/INRAE/UM/CIRAD, Montpellier, France
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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30
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Pan H, Zhou ZQ, He GW, Zhou J, Jin K, Liu HH, Wang C, Yang H, Yu YB, Tian Y. Neorhizobium xiangyangii sp. nov., isolated from a highland barley cultivation soil in Qamdo, Tibet. Arch Microbiol 2022; 204:345. [PMID: 35604458 DOI: 10.1007/s00203-022-02961-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/28/2022] [Accepted: 05/04/2022] [Indexed: 12/15/2022]
Abstract
A novel Gram-negative, aerobic, rod-shaped and non-nitrogen fixing bacterium named T786T was isolated from a highland barley cultivation soil in Qamdo, Tibet Autonomous Region, PR China. Strain T786T grew at 5-30 ℃ and pH 6.0-10.0 (optimum, 20-25 ℃ and pH 7.0-8.0) with 0-4% (w/v) NaCl (optimum, 0%). The 16S rRNA gene sequences of strain T786T showed the highest similarity to Neorhizobium vignae CCBAU 05176T (98.7%), followed by Neorhizobium alkalisoli CCBAU 01393T (98.5%), Neorhizobium tomejilense T17_20T (98.4%), Neorhizobium huautlense S02T (98.4%), and Neorhizobium galegae ATCC 43677T (98.0%). Phylogenetic analysis based on 16S rRNA genes indicated that strain T786T was a new member of the genus Neorhizobium. The digital DNA-DNA hybridization and average nucleotide identity values between strain T786T and related strains were estimated as 20.2-20.6% and 76.6-80.0%, respectively. The genomic DNA G + C content based on the draft genome sequence was 60.2%. The major cellular fatty acids were Summed feature 8 (C18:1 ω7c or C18:1 ω6c), C16:0 and Summed feature 3 (C16:1 ω7c or C16:1 ω6c). The polar lipids were diphosphatidyl glycerol, phosphatidyl glycerol, phosphatidyl ethanolamine, phosphatidyl methyl ethanolamine, unidentified phospholipid and unidentified lipids (1-4). The isoprenoid quinone was ubiquinone-10. The DAP and sugar components of cell wall were meso-DAP and ribose, glucose, respectively. Based on phenotypic, phylogenetic, and genotypic data, for which the name Neorhizobium xiangyangii sp. nov. is proposed. The type strain is T786T (= JCM 35100T = CICC 25102T).
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Affiliation(s)
- Hu Pan
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China.,Institute of Agricultural Product Quality Standard and Testing Research, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, 850032, China
| | - Zi-Qiong Zhou
- School of Food Science, Tibet Institute of Agriculture and Animal Husbandry, Nyingchi, 860000, China
| | - Guo-Wei He
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Jie Zhou
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Kai Jin
- Agricultural Technology Extension Service Center of Tibet, Lhasa, 850032, China
| | - Hu-Hu Liu
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Chong Wang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Hui Yang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Yao-Bin Yu
- Institute of Agricultural Product Quality Standard and Testing Research, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, 850032, China.
| | - Yun Tian
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China.
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New Insights into the Taxonomy of Bacteria in the Genomic Era and a Case Study with Rhizobia. Int J Microbiol 2022; 2022:4623713. [PMID: 35637770 PMCID: PMC9148247 DOI: 10.1155/2022/4623713] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 05/09/2022] [Indexed: 12/15/2022] Open
Abstract
Since early studies, the history of prokaryotes taxonomy has dealt with many changes driven by the development of new and more robust technologies. As a result, the number of new taxa descriptions is exponentially increasing, while an increasing number of others has been subject of reclassification, demanding from the taxonomists more effort to maintain an organized hierarchical system. However, expectations are that the taxonomy of prokaryotes will acquire a more stable status with the genomic era. Other analyses may continue to be necessary to determine microbial features, but the use of genomic data might be sufficient to provide reliable taxa delineation, helping taxonomy to reach the goal of correct classification and identification. Here we describe the evolution of prokaryotes' taxonomy until the genomic era, emphasizing bacteria and taking as an example the history of rhizobia taxonomy. This example was chosen because of the importance of the symbiotic nitrogen fixation of legumes with rhizobia to the nitrogen input to both natural ecosystems and agricultural crops. This case study reports the technological advances and the methodologies used to classify and identify bacterial species and indicates the actual rules required for an accurate description of new taxa.
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Bouchiba Y, Esque J, Cottret L, Maréchaux M, Gaston M, Gasciolli V, Keller J, Nouwen N, Gully D, Arrighi J, Gough C, Lefebvre B, Barbe S, Bono J. An integrated approach reveals how lipo‐chitooligosaccharides interact with the lysin motif receptor‐like kinase
MtLYR3. Protein Sci 2022; 31:e4327. [PMID: 35634776 PMCID: PMC9115844 DOI: 10.1002/pro.4327] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 11/22/2022]
Abstract
N‐acetylglucosamine containing compounds acting as pathogenic or symbiotic signals are perceived by plant‐specific Lysin Motif Receptor‐Like Kinases (LysM‐RLKs). The molecular mechanisms of this perception are not fully understood, notably those of lipo‐chitooligosaccharides (LCOs) produced during root endosymbioses with nitrogen‐fixing bacteria or arbuscular mycorrhizal fungi. In Medicago truncatula, we previously identified the LysM‐RLK LYR3 (MtLYR3) as a specific LCO‐binding protein. We also showed that the absence of LCO binding to LYR3 of the non‐mycorrhizal Lupinus angustifolius, (LanLYR3), was related to LysM3, which differs from that of MtLYR3 by several amino acids and, particularly, by a critical tyrosine residue absent in LanLYR3. Here, we aimed to define the LCO binding site of MtLYR3 by using molecular modelling and simulation approaches, combined with site‐directed mutagenesis and LCO binding experiments. 3D models of MtLYR3 and LanLYR3 ectodomains were built, and homology modelling and molecular dynamics (MD) simulations were performed. Molecular docking and MD simulation on the LysM3 identified potential key residues for LCO binding. We highlighted by steered MD simulations that in addition to the critical tyrosine, two other residues were important for LCO binding in MtLYR3. Substitution of these residues in LanLYR3‐LysM3 by those of MtLYR3‐LysM3 allowed the recovery of high‐affinity LCO binding in experimental radioligand‐binding assays. An analysis of selective constraints revealed that the critical tyrosine has experienced positive selection pressure and is absent in some LYR3 proteins. These findings now pave the way to uncover the functional significance of this specific evolutionary pattern.
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Affiliation(s)
- Younes Bouchiba
- TBI, Université de Toulouse CNRS, INRAE, INSA Toulouse France
| | - Jérémy Esque
- TBI, Université de Toulouse CNRS, INRAE, INSA Toulouse France
| | - Ludovic Cottret
- LIPME, Université de Toulouse INRAE, CNRS Castanet‐Tolosan France
| | - Maude Maréchaux
- LIPME, Université de Toulouse INRAE, CNRS Castanet‐Tolosan France
| | - Mégane Gaston
- LIPME, Université de Toulouse INRAE, CNRS Castanet‐Tolosan France
| | | | - Jean Keller
- Laboratoire de Recherche en Sciences Végétales Université de Toulouse, CNRS, UPS Castanet‐Tolosan France
| | - Nico Nouwen
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM) UMR IRD/SupAgro/INRAE/UM/CIRAD Montpellier France
| | - Djamel Gully
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM) UMR IRD/SupAgro/INRAE/UM/CIRAD Montpellier France
| | - Jean‐François Arrighi
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM) UMR IRD/SupAgro/INRAE/UM/CIRAD Montpellier France
| | - Clare Gough
- LIPME, Université de Toulouse INRAE, CNRS Castanet‐Tolosan France
| | - Benoit Lefebvre
- LIPME, Université de Toulouse INRAE, CNRS Castanet‐Tolosan France
| | - Sophie Barbe
- TBI, Université de Toulouse CNRS, INRAE, INSA Toulouse France
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Sun L, Zhang Z, Dong X, Tang Z, Ju B, Du Z, Wang E, Xie Z. Bradyrhizobium aeschynomenes sp. nov., a root and stem nodule microsymbiont of Aeschynomene indica. Syst Appl Microbiol 2022; 45:126337. [DOI: 10.1016/j.syapm.2022.126337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/15/2022] [Accepted: 05/23/2022] [Indexed: 10/18/2022]
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Shamseldin A. Future Outlook of Transferring Biological Nitrogen Fixation (BNF) to Cereals and Challenges to Retard Achieving this Dream. Curr Microbiol 2022; 79:171. [PMID: 35476236 DOI: 10.1007/s00284-022-02852-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 03/21/2022] [Indexed: 11/03/2022]
Abstract
BNF is a fascinating phenomenon which contributes to protect the nature from environmental pollution that can be happened as a result of heavy nitrogen applications. The importance of BNF is due to its supply of the agricultural lands with about 200 million tons of N annually. In this biological process, a specific group of bacteria collectively called rhizobia fix the atmospheric N in symbiosis with legumes called symbiotic nitrogen fixation and others (free living) fix nitrogen gas from the atmosphere termed asymbiotic. Several trials were done by scientists around the world to make cereals more benefited from nitrogen gas through different approaches. The first approach is to engineer cereals to form nodulated roots. Secondly is to transfer nif genes directly to cereals and fix N without Rhizobium partner. The other two approaches are maximizing the inoculation of cereals with both of diazotrophs or endophytes. Recently, scientists solved some challenges that entangle engineering cereals with nif genes directly and they confirmed the suitability of mitochondria and plastids as a suitable place for better biological function of nif genes expression in cereals. Fortunately, this article is confirming the success of scientists not only to transfer synthetic nitrogenase enzyme to Escherichia coli that gave 50% of its activity of expression, but also move it to plants as Nicotiana benthamiana. This mini review aims at explaining the future outlook of BNF and the challenges limiting its transfer to cereals and levels of success to make cereals self nitrogen fixing.
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Affiliation(s)
- Abdelaal Shamseldin
- Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City of Scientific Research and Technological Applications, New Borg El Arab, Alexandria, Egypt.
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Wang D, Dong W, Murray J, Wang E. Innovation and appropriation in mycorrhizal and rhizobial Symbioses. THE PLANT CELL 2022; 34:1573-1599. [PMID: 35157080 PMCID: PMC9048890 DOI: 10.1093/plcell/koac039] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 01/21/2022] [Indexed: 05/20/2023]
Abstract
Most land plants benefit from endosymbiotic interactions with mycorrhizal fungi, including legumes and some nonlegumes that also interact with endosymbiotic nitrogen (N)-fixing bacteria to form nodules. In addition to these helpful interactions, plants are continuously exposed to would-be pathogenic microbes: discriminating between friends and foes is a major determinant of plant survival. Recent breakthroughs have revealed how some key signals from pathogens and symbionts are distinguished. Once this checkpoint has been passed and a compatible symbiont is recognized, the plant coordinates the sequential development of two types of specialized structures in the host. The first serves to mediate infection, and the second, which appears later, serves as sophisticated intracellular nutrient exchange interfaces. The overlap in both the signaling pathways and downstream infection components of these symbioses reflects their evolutionary relatedness and the common requirements of these two interactions. However, the different outputs of the symbioses, phosphate uptake versus N fixation, require fundamentally different components and physical environments and necessitated the recruitment of different master regulators, NODULE INCEPTION-LIKE PROTEINS, and PHOSPHATE STARVATION RESPONSES, for nodulation and mycorrhization, respectively.
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Affiliation(s)
- Dapeng Wang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Wentao Dong
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | | | - Ertao Wang
- Authors for correspondence: (E.W) and (J.M.)
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Abstract
Root nodulating rhizobia are nearly ubiquitous in soils and provide the critical service of nitrogen fixation to thousands of legume species, including staple crops. However, the magnitude of fixed nitrogen provided to hosts varies markedly among rhizobia strains, despite host legumes having mechanisms to selectively reward beneficial strains and to punish ones that do not fix sufficient nitrogen. Variation in the services of microbial mutualists is considered paradoxical given host mechanisms to select beneficial genotypes. Moreover, the recurrent evolution of non-fixing symbiont genotypes is predicted to destabilize symbiosis, but breakdown has rarely been observed. Here, we deconstructed hundreds of genome sequences from genotypically and phenotypically diverse Bradyrhizobium strains and revealed mechanisms that generate variation in symbiotic nitrogen fixation. We show that this trait is conferred by a modular system consisting of many extremely large integrative conjugative elements and few conjugative plasmids. Their transmissibility and propensity to reshuffle genes generate new combinations that lead to uncooperative genotypes and make individual partnerships unstable. We also demonstrate that these same properties extend beneficial associations to diverse host species and transfer symbiotic capacity among diverse strains. Hence, symbiotic nitrogen fixation is underpinned by modularity, which engenders flexibility, a feature that reconciles evolutionary robustness and instability. These results provide new insights into mechanisms driving the evolution of mobile genetic elements. Moreover, they yield a new predictive model on the evolution of rhizobial symbioses, one that informs on the health of organisms and ecosystems that are hosts to symbionts and that helps resolve the long-standing paradox.
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Wang T, Balla B, Kovács S, Kereszt A. Varietas Delectat: Exploring Natural Variations in Nitrogen-Fixing Symbiosis Research. FRONTIERS IN PLANT SCIENCE 2022; 13:856187. [PMID: 35481136 PMCID: PMC9037385 DOI: 10.3389/fpls.2022.856187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
The nitrogen-fixing symbiosis between leguminous plants and soil bacteria collectively called rhizobia plays an important role in the global nitrogen cycle and is an essential component of sustainable agriculture. Genetic determinants directing the development and functioning of the interaction have been identified with the help of a very limited number of model plants and bacterial strains. Most of the information obtained from the study of model systems could be validated on crop plants and their partners. The investigation of soybean cultivars and different rhizobia, however, has revealed the existence of ineffective interactions between otherwise effective partners that resemble gene-for-gene interactions described for pathogenic systems. Since then, incompatible interactions between natural isolates of model plants, called ecotypes, and different bacterial partner strains have been reported. Moreover, diverse phenotypes of both bacterial mutants on different host plants and plant mutants with different bacterial strains have been described. Identification of the genetic factors behind the phenotypic differences did already and will reveal novel functions of known genes/proteins, the role of certain proteins in some interactions, and the fine regulation of the steps during nodule development.
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Affiliation(s)
- Ting Wang
- Eötvös Loránd Research Network, Biological Research Centre, Institute of Plant Biology, Szeged, Hungary
- Doctoral School in Biology, University of Szeged, Szeged, Hungary
| | - Benedikta Balla
- Eötvös Loránd Research Network, Biological Research Centre, Institute of Plant Biology, Szeged, Hungary
- Doctoral School in Biology, University of Szeged, Szeged, Hungary
| | - Szilárd Kovács
- Eötvös Loránd Research Network, Biological Research Centre, Institute of Plant Biology, Szeged, Hungary
| | - Attila Kereszt
- Eötvös Loránd Research Network, Biological Research Centre, Institute of Plant Biology, Szeged, Hungary
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Teulet A, Camuel A, Perret X, Giraud E. The Versatile Roles of Type III Secretion Systems in Rhizobia-Legume Symbioses. Annu Rev Microbiol 2022; 76:45-65. [PMID: 35395168 DOI: 10.1146/annurev-micro-041020-032624] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To suppress plant immunity and promote the intracellular infection required for fixing nitrogen for the benefit of their legume hosts, many rhizobia use type III secretion systems (T3SSs) that deliver effector proteins (T3Es) inside host cells. As reported for interactions between pathogens and host plants, the immune system of legume hosts and the cocktail of T3Es secreted by rhizobia determine the symbiotic outcome. If they remain undetected, T3Es may reduce plant immunity and thus promote infection of legumes by rhizobia. If one or more of the secreted T3Es are recognized by the cognate plant receptors, defense responses are triggered and rhizobial infection may abort. However, some rhizobial T3Es can also circumvent the need for nodulation (Nod) factors to trigger nodule formation. Here we review the multifaceted roles played by rhizobial T3Es during symbiotic interactions with legumes. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Albin Teulet
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France;
| | - Alicia Camuel
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France; .,PHIM Plant Health Institute, IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France
| | - Xavier Perret
- Laboratory of Microbial Genetics, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Eric Giraud
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France; .,PHIM Plant Health Institute, IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France
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Novel metabolic interactions and environmental conditions mediate the boreal peatmoss-cyanobacteria mutualism. THE ISME JOURNAL 2022; 16:1074-1085. [PMID: 34845335 PMCID: PMC8941135 DOI: 10.1038/s41396-021-01136-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/24/2021] [Accepted: 10/01/2021] [Indexed: 11/18/2022]
Abstract
Interactions between Sphagnum (peat moss) and cyanobacteria play critical roles in terrestrial carbon and nitrogen cycling processes. Knowledge of the metabolites exchanged, the physiological processes involved, and the environmental conditions allowing the formation of symbiosis is important for a better understanding of the mechanisms underlying these interactions. In this study, we used a cross-feeding approach with spatially resolved metabolite profiling and metatranscriptomics to characterize the symbiosis between Sphagnum and Nostoc cyanobacteria. A pH gradient study revealed that the Sphagnum–Nostoc symbiosis was driven by pH, with mutualism occurring only at low pH. Metabolic cross-feeding studies along with spatially resolved matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) identified trehalose as the main carbohydrate source released by Sphagnum, which were depleted by Nostoc along with sulfur-containing choline-O-sulfate, taurine and sulfoacetate. In exchange, Nostoc increased exudation of purines and amino acids. Metatranscriptome analysis indicated that Sphagnum host defense was downregulated when in direct contact with the Nostoc symbiont, but not as a result of chemical contact alone. The observations in this study elucidated environmental, metabolic, and physiological underpinnings of the widespread plant–cyanobacterial symbioses with important implications for predicting carbon and nitrogen cycling in peatland ecosystems as well as the basis of general host-microbe interactions.
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Raul B, Bhattacharjee O, Ghosh A, Upadhyay P, Tembhare K, Singh A, Shaheen T, Ghosh AK, Torres-Jerez I, Krom N, Clevenger J, Udvardi M, Scheffler BE, Ozias-Akins P, Sharma RD, Bandyopadhyay K, Gaur V, Kumar S, Sinharoy S. Microscopic and Transcriptomic Analyses of Dalbergoid Legume Peanut Reveal a Divergent Evolution Leading to Nod-Factor-Dependent Epidermal Crack-Entry and Terminal Bacteroid Differentiation. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:131-145. [PMID: 34689599 DOI: 10.1094/mpmi-05-21-0122-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Root nodule symbiosis (RNS) is the pillar behind sustainable agriculture and plays a pivotal role in the environmental nitrogen cycle. Most of the genetic, molecular, and cell-biological knowledge on RNS comes from model legumes that exhibit a root-hair mode of bacterial infection, in contrast to the Dalbergoid legumes exhibiting crack-entry of rhizobia. As a step toward understanding this important group of legumes, we have combined microscopic analysis and temporal transcriptome to obtain a dynamic view of plant gene expression during Arachis hypogaea (peanut) nodule development. We generated comprehensive transcriptome data by mapping the reads to A. hypogaea, and two diploid progenitor genomes. Additionally, we performed BLAST searches to identify nodule-induced yet-to-be annotated peanut genes. Comparison between peanut, Medicago truncatula, Lotus japonicus, and Glycine max showed upregulation of 61 peanut orthologs among 111 tested known RNS-related genes, indicating conservation in mechanisms of nodule development among members of the Papilionoid family. Unlike model legumes, recruitment of class 1 phytoglobin-derived symbiotic hemoglobin (SymH) in peanut indicates diversification of oxygen-scavenging mechanisms in the Papilionoid family. Finally, the absence of cysteine-rich motif-1-containing nodule-specific cysteine-rich peptide (NCR) genes but the recruitment of defensin-like NCRs suggest a diverse molecular mechanism of terminal bacteroid differentiation. In summary, our work describes genetic conservation and diversification in legume-rhizobia symbiosis in the Papilionoid family, as well as among members of the Dalbergoid legumes.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Bikash Raul
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Oindrila Bhattacharjee
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
- Amity University Haryana, Amity Education Valley, Manesar, Panchgaon, Haryana 122412, India
| | - Amit Ghosh
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Priya Upadhyay
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Kunal Tembhare
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Ajeet Singh
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Tarannum Shaheen
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Asim Kumar Ghosh
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | | | - Nick Krom
- Noble Research Institute, 2510 Sam Noble Pkwy, Ardmore, OK 73401, U.S.A
| | - Josh Clevenger
- University of Georgia, Institute of Plant Breeding, Genetics and Genomics and Department of Horticulture, Tifton, GA 31793, U.S.A
| | - Michael Udvardi
- Noble Research Institute, 2510 Sam Noble Pkwy, Ardmore, OK 73401, U.S.A
| | - Brian E Scheffler
- United States Department of Agriculture-Agricultural Research Service Jamie Whitten Delta States Research Center (JWDSRC) Stoneville, JWDSRC, Bldg.1, Room 229, Experiment Station Road, PO Box 36, Stoneville, MS 38776-0036, U.S.A
| | - Peggy Ozias-Akins
- University of Georgia, Institute of Plant Breeding, Genetics and Genomics and Department of Horticulture, Tifton, GA 31793, U.S.A
| | - Ravi Datta Sharma
- Amity University Haryana, Amity Education Valley, Manesar, Panchgaon, Haryana 122412, India
| | - Kaustav Bandyopadhyay
- Amity University Haryana, Amity Education Valley, Manesar, Panchgaon, Haryana 122412, India
| | - Vineet Gaur
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Shailesh Kumar
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Senjuti Sinharoy
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
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42
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Stoyancheva G, Dishliyska V, Miteva‐Staleva J, Kostadinova N, Abrashev R, Angelova M, Krumova E. Sequencing and gene expression analysis of catalase genes in Antarctic fungal strain Penicillium griseofulvum P29. Polar Biol 2022. [DOI: 10.1007/s00300-021-03001-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Guha S, Molla F, Sarkar M, Ibańez F, Fabra A, DasGupta M. Nod factor-independent 'crack-entry' symbiosis in dalbergoid legume Arachis hypogaea. Environ Microbiol 2022; 24:2732-2746. [PMID: 34995397 DOI: 10.1111/1462-2920.15888] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/09/2021] [Accepted: 12/21/2021] [Indexed: 11/29/2022]
Abstract
Dalbergoids are typified by crack-entry symbiosis which is evidenced to be Nod Factor (NF)- independent in several Aeschynomene legumes. Natural symbionts of the dalbergoid legume Arachis hypogaea are always NF-producing, prompting us to check whether symbiosis in this legume could also be NF-independent. For this, we followed the symbiosis with two NF containing bradyrhizobial strains- SEMIA6144, a natural symbiont of Arachis and ORS285, a versatile nodulator of Aeschynomene legumes, along with their corresponding nodulation (nod) mutants. Additionally, we investigated NF-deficient bradyrhizobia like BTAi1, a natural symbiont of Aeschynomene indica and the WBOS strains that were natural endophytes of Oryza sativa, collected from an Arachis-Oryza intercropped field. While SEMIA6144ΔnodC was non-nodulating, both ORS285 and ORS285ΔnodB could induce functional nodulation, although with lower efficiency than SEMIA6144. On the other hand, all the NF-deficient strains- BTAi1, WBOS2 and WBOS4 showed comparable nodulation with ORS285 indicating Arachis to harbour a NF-independent mechanism of symbiosis. Intriguingly, symbiosis in Arachis, irrespective of whether it was NF-dependent or independent, was always associated with the curling or branching of the rosette root hairs at the lateral root bases. Thus, despite being predominantly described as NF-dependent legume, Arachis does retain a vestigial, less-efficient form of NF-independent symbiosis. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Sohini Guha
- Department of Biochemistry, University of Calcutta, Kolkata, 700019, India
| | - Firoz Molla
- Department of Biochemistry, University of Calcutta, Kolkata, 700019, India
| | - Monolina Sarkar
- Department of Biochemistry, University of Calcutta, Kolkata, 700019, India
| | - Fernando Ibańez
- Instituto de Investigaciones Agrobiotecnologicas (CONCINET-UNRC), Ruta 36 Km 601, Río Cuarto, Argentina
| | - Adriana Fabra
- Instituto de Investigaciones Agrobiotecnologicas (CONCINET-UNRC), Ruta 36 Km 601, Río Cuarto, Argentina
| | - Maitrayee DasGupta
- Department of Biochemistry, University of Calcutta, Kolkata, 700019, India
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Rodríguez-Esperón MC, Eastman G, Sandes L, Garabato F, Eastman I, Iriarte A, Fabiano E, Sotelo-Silveira JR, Platero R. Genomics and transcriptomics insights into luteolin effects on the beta-rhizobial strain Cupriavidus necator UYPR2.512. Environ Microbiol 2021; 24:240-264. [PMID: 34811861 DOI: 10.1111/1462-2920.15845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 11/04/2021] [Accepted: 11/08/2021] [Indexed: 11/28/2022]
Abstract
Cupriavidus necator UYPR2.512 is a rhizobial strain that belongs to the Beta-subclass of proteobacteria, able to establish successful symbiosis with Mimosoid legumes. The initial steps of rhizobium-legumes symbioses involve the reciprocal recognition by chemical signals, being luteolin one of the molecules involved. However, there is a lack of information on the effect of luteolin in beta-rhizobia. In this work, we used long-read sequencing to complete the genome of UYPR2.512 providing evidence for the existence of four closed circular replicons. We used an RNA-Seq approach to analyse the response of UYPR2.512 to luteolin. One hundred and forty-five genes were differentially expressed, with similar numbers of downregulated and upregulated genes. Most repressed genes were mapped to the main chromosome, while the upregulated genes were overrepresented among pCne512e, containing the symbiotic genes. Induced genes included the nod operon and genes implicated in exopolysaccharides and flagellar biosynthesis. We identified many genes involved in iron, copper and other heavy metals metabolism. Among repressed genes, we identified genes involved in basal carbon and nitrogen metabolism. Our results suggest that in response to luteolin, C. necator strain UYPR2.512 reshapes its metabolism in order to be prepared for the forthcoming symbiotic interaction.
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Affiliation(s)
- M C Rodríguez-Esperón
- Laboratorio de Microbiología Ambiental, Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - G Eastman
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - L Sandes
- Laboratorio de Microbiología Ambiental, Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - F Garabato
- Laboratorio de Microbiología Ambiental, Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - I Eastman
- Laboratorio de Microbiología Ambiental, Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - A Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Facultad de Medicina, Instituto de Higiene, Montevideo, Uruguay
| | - E Fabiano
- Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - J R Sotelo-Silveira
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - R Platero
- Laboratorio de Microbiología Ambiental, Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
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Feng Y, Wu P, Liu C, Peng L, Wang T, Wang C, Tan Q, Li B, Ou Y, Zhu H, Yuan S, Huang R, Stacey G, Zhang Z, Cao Y. Suppression of LjBAK1-mediated immunity by SymRK promotes rhizobial infection in Lotus japonicus. MOLECULAR PLANT 2021; 14:1935-1950. [PMID: 34314895 DOI: 10.1016/j.molp.2021.07.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 03/07/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
An important question in biology is how organisms can associate with different microbes that pose no threat (commensals), pose a severe threat (pathogens), and those that are beneficial (symbionts). The root nodule symbiosis serves as an important model system for addressing such questions in the context of plant-microbe interactions. It is now generally accepted that rhizobia can actively suppress host immune responses during the infection process, analogous to the way in which plant pathogens can evade immune recognition. However, much remains to be learned about the mechanisms by which the host recognizes the rhizobia as pathogens and how, subsequently, these pathways are suppressed to allow establishment of the nitrogen-fixing symbiosis. In this study, we found that SymRK (Symbiosis Receptor-like Kinase) is required for rhizobial suppression of plant innate immunity in Lotus japonicus. SymRK associates with LjBAK1 (BRASSINOSTEROID INSENSITIVE 1-Associated receptor Kinase 1), a well-characterized positive regulator of plant innate immunity, and directly inhibits LjBAK1 kinase activity. Rhizobial inoculation enhances the association between SymRK and LjBAK1 in planta. LjBAK1 is required for the regulation of plant innate immunity and plays a negative role in rhizobial infection in L. japonicus. The data indicate that the SymRK-LjBAK1 protein complex serves as an intersection point between rhizobial symbiotic signaling pathways and innate immunity pathways, and support that rhizobia may actively suppress the host's ability to mount a defense response during the legume-rhizobium symbiosis.
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Affiliation(s)
- Yong Feng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Ping Wu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Chao Liu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Liwei Peng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Tao Wang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Chao Wang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Qian Tan
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Bixuan Li
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yajuan Ou
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Hui Zhu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Songli Yuan
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Renliang Huang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Gary Stacey
- Divisions of Plant Sciences and Biochemistry, C. S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Zhongming Zhang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yangrong Cao
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
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Evolutionary origin and ecological implication of a unique nif island in free-living Bradyrhizobium lineages. THE ISME JOURNAL 2021; 15:3195-3206. [PMID: 33990706 PMCID: PMC8528876 DOI: 10.1038/s41396-021-01002-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/21/2021] [Accepted: 04/28/2021] [Indexed: 02/03/2023]
Abstract
The alphaproteobacterial genus Bradyrhizobium has been best known as N2-fixing members that nodulate legumes, supported by the nif and nod gene clusters. Recent environmental surveys show that Bradyrhizobium represents one of the most abundant free-living bacterial lineages in the world's soils. However, our understanding of Bradyrhizobium comes largely from symbiotic members, biasing the current knowledge of their ecology and evolution. Here, we report the genomes of 88 Bradyrhizobium strains derived from diverse soil samples, including both nif-carrying and non-nif-carrying free-living (nod free) members. Phylogenomic analyses of these and 252 publicly available Bradyrhizobium genomes indicate that nif-carrying free-living members independently evolved from symbiotic ancestors (carrying both nif and nod) multiple times. Intriguingly, the nif phylogeny shows that the vast majority of nif-carrying free-living members comprise an independent cluster, indicating that horizontal gene transfer promotes nif expansion among the free-living Bradyrhizobium. Comparative genomics analysis identifies that the nif genes found in free-living Bradyrhizobium are located on a unique genomic island of ~50 kb equipped with genes potentially involved in coping with oxygen tension. We further analyze amplicon sequencing data to show that Bradyrhizobium members presumably carrying this nif island are widespread in a variety of environments. Given the dominance of Bradyrhizobium in world's soils, our findings have implications for global nitrogen cycles and agricultural research.
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The Type III Effectome of the Symbiotic Bradyrhizobium vignae Strain ORS3257. Biomolecules 2021; 11:biom11111592. [PMID: 34827590 PMCID: PMC8615406 DOI: 10.3390/biom11111592] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022] Open
Abstract
Many Bradyrhizobium strains are able to establish a Nod factor-independent symbiosis with the leguminous plant Aeschynomene indica by the use of a type III secretion system (T3SS). Recently, an important advance in the understanding of the molecular factors supporting this symbiosis has been achieved by the in silico identification and functional characterization of 27 putative T3SS effectors (T3Es) of Bradyrhizobium vignae ORS3257. In the present study, we experimentally extend this catalog of T3Es by using a multi-omics approach. Transcriptome analysis under non-inducing and inducing conditions in the ORS3257 wild-type strain and the ttsI mutant revealed that the expression of 18 out of the 27 putative effectors previously identified, is under the control of TtsI, the global transcriptional regulator of T3SS and T3Es. Quantitative shotgun proteome analysis of culture supernatant in the wild type and T3SS mutant strains confirmed that 15 of the previously determined candidate T3Es are secreted by the T3SS. Moreover, the combined approaches identified nine additional putative T3Es and one of them was experimentally validated as a novel effector. Our study underscores the power of combined proteome and transcriptome analyses to complement in silico predictions and produce nearly complete effector catalogs. The establishment of the ORS3257 effectome will form the basis for a full appraisal of the symbiotic properties of this strain during its interaction with various host legumes via different processes.
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Nouwen N, Chaintreuil C, Fardoux J, Giraud E. A glutamate synthase mutant of Bradyrhizobium sp. strain ORS285 is unable to induce nodules on Nod factor-independent Aeschynomene species. Sci Rep 2021; 11:20910. [PMID: 34686745 PMCID: PMC8536739 DOI: 10.1038/s41598-021-00480-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/11/2021] [Indexed: 11/09/2022] Open
Abstract
The Bradyrhizobium sp. strain ORS285 is able to establish a nitrogen-fixing symbiosis with both Nod factor (NF) dependent and NF-independent Aeschynomene species. Here, we have studied the growth characteristics and symbiotic interaction of a glutamate synthase (GOGAT; gltD::Tn5) mutant of Bradyrhizobium ORS285. We show that the ORS285 gltD::Tn5 mutant is unable to use ammonium, nitrate and many amino acids as nitrogen source for growth and is unable to fix nitrogen under free-living conditions. Moreover, on several nitrogen sources, the growth rate of the gltB::Tn5 mutant was faster and/or the production of the carotenoid spirilloxanthin was much higher as compared to the wild-type strain. The absence of GOGAT activity has a drastic impact on the symbiotic interaction with NF-independent Aeschynomene species. With these species, inoculation with the ORS285 gltD::Tn5 mutant does not result in the formation of nodules. In contrast, the ORS285 gltD::Tn5 mutant is capable to induce nodules on NF-dependent Aeschynomene species, but these nodules were ineffective for nitrogen fixation. Interestingly, in NF-dependent and NF-independent Aeschynomene species inoculation with the ORS285 gltD::Tn5 mutant results in browning of the plant tissue at the site of the infection suggesting that the mutant bacteria induce plant defence responses.
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Affiliation(s)
- Nico Nouwen
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRAE/Université de Montpellier/CIRAD - Campus de Baillarguet, Montpellier, France.
| | - Clémence Chaintreuil
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRAE/Université de Montpellier/CIRAD - Campus de Baillarguet, Montpellier, France
| | - Joel Fardoux
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRAE/Université de Montpellier/CIRAD - Campus de Baillarguet, Montpellier, France
| | - Eric Giraud
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRAE/Université de Montpellier/CIRAD - Campus de Baillarguet, Montpellier, France
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Schaedel M, Hidrobo G, Grossman J. From Microns to Meters: Exploring Advances in Legume Microbiome Diversity for Agroecosystem Benefits. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2021. [DOI: 10.3389/fsufs.2021.668195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Legumes are of primary importance for agroecosystems because they provide protein-rich foods and enhance soil fertility through fixed atmospheric nitrogen. The legume-rhizobia symbiosis that makes this possible has been extensively studied, from basic research on biochemical signaling to practical applications in cropping systems. While rhizobia are the most-studied group of associated microorganisms, the functional benefit they confer to their legume hosts by fixing nitrogen is not performed in isolation. Indeed, non-rhizobia members of the rhizosphere and nodule microbiome are now understood to contribute in multiple ways to nodule formation, legume fitness, and other agroecosystem services. In this review, we summarize advances contributing to our understanding of the diversity and composition of bacterial members of the belowground legume microbiome. We also highlight applied work in legume food and forage crops that link microbial community composition with plant functional benefits. Ultimately, further research will assist in the development of multi-species microbial inoculants and cropping systems that maximize plant nutrient benefits, while reducing sources of agricultural pollution.
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Khokhani D, Carrera Carriel C, Vayla S, Irving TB, Stonoha-Arther C, Keller NP, Ané JM. Deciphering the Chitin Code in Plant Symbiosis, Defense, and Microbial Networks. Annu Rev Microbiol 2021; 75:583-607. [PMID: 34623896 DOI: 10.1146/annurev-micro-051921-114809] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chitin is a structural polymer in many eukaryotes. Many organisms can degrade chitin to defend against chitinous pathogens or use chitin oligomers as food. Beneficial microorganisms like nitrogen-fixing symbiotic rhizobia and mycorrhizal fungi produce chitin-based signal molecules called lipo-chitooligosaccharides (LCOs) and short chitin oligomers to initiate a symbiotic relationship with their compatible hosts and exchange nutrients. A recent study revealed that a broad range of fungi produce LCOs and chitooligosaccharides (COs), suggesting that these signaling molecules are not limited to beneficial microbes. The fungal LCOs also affect fungal growth and development, indicating that the roles of LCOs beyond symbiosis and LCO production may predate mycorrhizal symbiosis. This review describes the diverse structures of chitin; their perception by eukaryotes and prokaryotes; and their roles in symbiotic interactions, defense, and microbe-microbe interactions. We also discuss potential strategies of fungi to synthesize LCOs and their roles in fungi with different lifestyles.
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Affiliation(s)
- Devanshi Khokhani
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , , .,Current affiliation: Department of Plant Pathology, University of Minnesota, Saint Paul, Minnesota 55108, USA;
| | - Cristobal Carrera Carriel
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , ,
| | - Shivangi Vayla
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , ,
| | - Thomas B Irving
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , ,
| | - Christina Stonoha-Arther
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , ,
| | - Nancy P Keller
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , , .,Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Jean-Michel Ané
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , , , , , .,Department of Agronomy, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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